Female contact blade

ABSTRACT

A female contact blade is made economically, having good spring tension to each leg, one leg portion made of two sections, each supported by a shoulder.

United States Patn [191 Pfeifer 1 1 July 9, 1974 [54] FEMALE CQNTACT BLADE PN 3,115,244 12/1963 Laskowski 339/276 SF 3,268,847 8/1966 Klum Jr 339/218 R [75] Inventor: sprmgfield 3,713,079 1/1973 Dech lgtte 339/258?" [731 Assigneei 2 9 g i g cmpany FOREIGN PATENTS OR APPLICATIONS emwor 1,109,373 4/1968 Great Britain 339/276 SF [22] Filed: Sept. 5, 1972 [21 Appl NO: 2 202 Primary Examiner-James R. Boler Assistant Examiner-Peter Nerbun Attorney, Agent, or Firm-Auslander & Thomas [52] US. Cl 339/251 [51] Int. Cl H011 11/22 581 Field of Search 339/258, 259, 276 SP, 256 [57] ABSTRACT A female contact blade is made economically, having 5 Refe en e Cit d good spring tension to each leg, one leg portion made UNITED STATES PATENTS of two sections, each supported by a shoulder.

3,058,091 10/1962 Henschen 339/259 R 7 Claims, 16 Drawing Figures PATENTEBJUL 91974 v sum 1 or 2 eat mmmm

mm mw mm The present invention relates to an improved female electrical blade and a method for manufacture of blades.

The present invention is preferably used in a female socket or outlet for usual home and industrial uses although other applications may be found.

In particular, where a female socket is at the end of a length of wire, the female contacts of the present invention provide a stronger and less expensive contact than contacts of the past.

By fabricating female contacts by the progressive stamping of a workpiece, speed and economy have been achieved in the past. The stamping strip usually held completed female contacts fully formed, ready to be fed to a crimping machine to be joined to wires.

In the past, one problem of such progressive stamping of female contact blades has been the high percentage of scrap metal cut away in the formation of the contact. The scrap factor is an important element of cost.

Most of the progressively stamped blades are made by overlapping longitudinalfolds of the metal to appose the two leg portions of the female blade for grasping a male contact blade. A second problem encountered in the stamping of female contact blades was one of maintaining strength and springiness to the apposed legs. Some leg folds were unsupported, passing between the crimp arms of the female blade. Such blades, when crimped, were often twisted, weak or generally misaligned. Some complicated blades included laterally crimped shoulders.

One blade of the past, substantially overcoming the scrap waste factor, produced a blade folded outward 90 from the plane of the stamping strip. Unfortunately, such blade had its legs supported for a small distance on one side, thus the spring grip of the legs was poor or easily loosened.

According to the present invention, a new female electric contact blade is made on a stamping strip, saving a larger percentage of former scrap wastage and producing a female contact blade with good support of its leg and good long-life spring of the legs.

Although such novel feature or features believed to be characteristic of the invention are pointed out in the FIG. 9 is a side elevation of a severed female contact blade made as shown in FIG. 3.

FIG. 10 is another embodiment of a single crimped and severed female contact blade of the present inventlon.

FIG. 11 is a progressive stamping strip for making the female contact blade of FIG. 10.

FIG. 12 is an end elevation of the U bind of a female contact blade on the stamping strip of FIG. 10.

FIG. 13 is an end elevation of a fold of a female contact blade on the stamping strip of FIG. 10.

FIG. 14 is an end elevation of a completed female contact blade on the stamping strip of FIG. 10.

FIG. 15 is a crimp end elevation. of a severed female contact blade made as shown in FIG. 14.

FIG. 16 is a side elevation of a severed female contact blade as shown in FIG. 10.

Referring now to the figures in greater detail, where like reference numbers denote like parts in the various figures.

The female contact blade, as shown in FIG. 1 is the prior art where the folded blade required crimped shoulders to provide strength to the legs and the blades in being made on the stamping as shown, had a scrap waste in some instances, as high as double the scrap waste in the making of the female contact blade of the present invention and its embodiments.

In FIG. 2, a preferred embodiment of the female.

contact blade 10, the female contact blade 10 is held to the stamping strip 1 l by an outer strip 12. As can be seen in FIG. 3, the first perforation l3 outlines the outer periphery of the female contact blade 10 as it is attached to the outer strip 12 and defines the crimp arms 14. The leg portions 15, l6, 17 are then slit by slits l8, 19 .The workpiece on the stamping strip 11 is then provided with indentations 20, 21, 22 which ultimately form the spring action bowing of the legs 23, 24 and lip indentations 25, 26, 27 bend back the leg portions 15, 16, 17 so the completed female contact blade 10 will have lip 28 to help guide a male blade into contact.

The crimp arms 14 may be bent partially upward in a succeeding step. In successive steps then, the crimp claims, the invention and the manner in which it may be carried out may be further understood by reference to the description following and the accompanying drawings.

FIG. I is a stamping strip of a double folded female contact blade of the prior art. 7

FIG. 2 is a single severed female contact blade of the present invention.

FIG. 3 is a progressive stamping strip for making the female contact blade of FIG. 2.

FIG. 4 is the female contact blade such'as in FIGS. 2 and 3 with a wire in between the crimp arms. I

FIG. 5 is an end elevation of the U" bend of a fe male contact blade on the stamping strip of FIG. 3.

FIG. 6 is an end elevation of a fold of a female contact blade on the stamping strip of FIG. 3.

FIG. 7 is an end elevation of a completed female contact blade on the stamping strip of FIG. 3.

FIG. 8 is a crimp end elevation of the female contact blade of FIG. 7.

arms 14 may be completed while the leg portions 15, 17 are bent upward preferably perpendicular to the leg portion 16, as seen in FIG. 5, then further bent over as seen in FIG. 6 and finally completed as seen in FIG. 8.

It may be advantageous to shape and lengthen the arms 14 by swedging. This can be one most effectively posed, in effect, as a second blade portion.

The female contact blade 31 is made from a stamping strip 32 which, when stamped into female contact blades 31, saves even more scrap then the other preferred embodiments heretofore described.

The first slits 33, 34 define a connecting strip 35, leg perforations 36, 37 are then stamped out, the female blades 31 are separated by slits 38 and the crimp arms 39, 40 are defined. Indentations 41, 42, 43 are provided on the blade portions for the: bowing of the legs 3 47, 48 and indentations 49, 50, 51 are provided so that the complete female blade 31 with free legs 47, 48 may have a lip 52 to help guide a male contact blade and hold it under spring tension.

The leg portions 44, 45, 46 are most preferably bent perpendicularly as shown in FIG. 12, then partially closed as shown in FIG. 13 until finally the crimp arms 39, 40 are shaped in position as shown in FIG. 15 and the legs 47, 48 closed against each other as seen in FIG. 14.

The shoulders 53, 54 extend along the longitudinal length of the female contact blade 31, holding the leg portions 44, 46 firmly as a unitary functioning leg 47.

In operation, the female contact blade has the advantage of having the outer strip 12 beyond the crimp arms 14; thus, in machine crimping it is a bit easier to sever the female contact blade 10 and crimp lead wires.

Because the outer strip is on the outside, optionally the blade length may be reduced where desired, since the distance between the crimp arms 14 and the legs 23, 24 is not straddled by a connecting strip 35.

The top of the leg portions l5, 17 are downsloping, as can be seen in FIG. 4, and form a recess 55 or declivity. so the wire 56 can pass even beyond the crimp arms 14, to be thoroughly gripped in a shorter female blade The female contact blade 31 functions in the same manner as the female contact blade 10, the major exception being that in machine crimping (not shown) the ends of the connecting strip 35 are usually severed when the wire 56 is crimped as shown in FIG. 10. The width of the connecting strip 35 gives more latitude for the wires 56 to extend.

By providing leg portions 15, 17, 44, 46, jointed to a female contact blade 10, 31, held by shoulders 29, 30, 53, 54, the disadvantages of the weakness of the prior art double folded blade is overcome by two leg portions forming one leg 24, 47, each portion of which l5, 17, 44, 46 is held firm by a shoulder 29, 30, 53, 54. There is little likeliness of twisting or losing spring tension and the complicated folds and cuts necessary to make a female contact blade such as shown in FIG. 1 are avoided with a great saving of scrap metal in the course of stamping.

The terms and expressions which are employed are used as terms of description; it is recognized, though, that van'ous modifications are possible.

Having thus described certain forms of the invention in some detail, what is claimed is:

1. A one-piece female contact blade comprising a first blade portion, said first blade portion being of one piece, said first blade portion including wire crimping means, said wire crimping means extending from one end of said first blade portion, a second blade portion, said second blade portion including two sections, each said section held to said first blade portion by shoulders that are of one-piece construction with said first blade portion, said two blade sections juxtaposed along their length and overlapping said first blade portion inward from said shoulders, said two blade sections overlying and in contact with said first blade portion and unsupported from said shoulders to said blades other end, said first and second blade portions adapted to receive a male blade all in parallel.

2. The invention of claim 1 wherein upper portions of said first blade portion and second blade portions are indented and bowed as between each other.

3. The invention of claim 1 wherein said first blade portion and second blade portions include bent lips at their ends.

4. The invention of claim 1 wherein said wire crimp means is a pair of upswept crimp arms.

5. The invention of claim 1 including a stamping strip with a plurality of female contact blades joined by a connecting strip at said blades crimp ends.

6. The invention of claim ll including a stamping strip with a plurality of female contact blades joined by a connecting strip intermediate the ends of said blades.

7. The invention of claim 1 wherein each of said two sections of said second blade portion has a downsweeping portion on its top portion near the crimp end of said female contact blade to form a recess between said two blade sections. 

1. A one-piece female contact blade comprising a first blade portion, said first blade portion being of one piece, said first blade portion including wire crimping means, said wire crimping means extending from one end of said first blade portion, a second blade portion, said second blade portion including two sections, each said section held to said first blade portion by shoulders that are of one-piece construction with said first blade portion, said two blade sections juxtaposed along their length and overlapping said first blade portion inward from said shoulders, said two blade sections overlying and in contact with said first blade portion and unsupported from said shoulders to said blade''s other end, said first and second blade portions adapted to receive a male blade all in parallel.
 2. The invention of claim 1 wherein upper portions of said first blade portion and second blade portions are indented and bowed as between each other.
 3. The invention of claim 1 wherein said first blade portion and second blade portions include bent lips at their ends.
 4. The invention of claim 1 wherein said wire crimp means is a pair of upswept crimp arms.
 5. The invention of claim 1 including a stamping strip with a plurality of female contact blades joined by a connecting strip at said blades'' crimp ends.
 6. The invention of claim 1 including a stamping strip with a plurality of female contact blades joined by a connecting strip intermediate the ends of said blades.
 7. The invention of claim 1 wherein each of said two sections of said second blade portion has a downsweeping portion on its top portion near the crimp end of said female contact blade to form a recess between said two blade sections. 